Opportunities for Improvement of Maternal Performance in the Lamb Industry

Performance of the ewe flock, mainly the number and weight of lambs sold, has a major impact on profitability of the lamb enterprise. However, genetic improvement in the maternal sector of the lamb industry lags behind that occurring in the terminal sire sector. A national central progeny test for maternal sires in the lamb industry was established in 1997 and the design and early results are presented. Sires are mated to Merino ewes at 3 sites (including link sires). 1stX wether progeny are slaughtered at heavy weights and 1stX ewe progeny are mated to terminal sires over 3 years, with their lambs slaughtered and wool production recorded. 1stX Meat estimated breeding values (EBVs) of 51 sires ranged from +8.2 to -6.9kg weight, -6.6 to +8.4mmGR fat and +1.9 to -1.9cm2 eye muscle area (http://ansc.une.edu.au/lambplan/mcpt). Maternal performance of 1stX daughter sire groups ranged from 2 to 22 kg for total weight of carcass per ewe joined at 7 months of age. Ranking of sires on lambing performance of 1stX daughters varied for matings in autumn and spring at one site. Implications of the results for genetic improvement in the maternal sector of the lamb industry are discussed.